Extensive combined experimental and theoretical investigations of the linear evolution of three-dimensional (3D) Tollmien-Schlichting (TS) instability modes of 3D boundary layers developing on a swept airfoil section have been carried out. The flow under consideration is the boundary layer over an airfoil at 35° sweep and an angle of attack of +1.5°. At these conditions, TS instability is found to be the predominant one. Perturbations with different frequencies and spanwise wavenumbers are generated in a controlled way using a row of elastic membranes. All experimental results are deeply processed and compared with results of calculations based on theoretical approaches. Very good quantitative agreement of all measured and calculated stability characteristics of swept-wing boundary layers is achieved.

1.
V. I.
Borodulin
,
A. V.
Ivanov
,
Y.
Kachanov
,
D.
Mischenko
,
R.
Örlü
,
A.
Hanifi
, and
S.
Hein
, “
Experimental and theoretical study of swept-wing boundary-layer instabilities. Unsteady crossflow instability
,”
Phys. Fluids
31
,
064101
(
2019
).
2.
V. R.
Gaponenko
,
A. V.
Ivanov
,
Y. S.
Kachanov
, and
J. D.
Crouch
, “
Swept-wing boundary-layer receptivity to surface non-uniformities
,”
J. Fluid Mech.
461
,
93
(
2002
).
3.
W. S.
Saric
,
H. L.
Reed
, and
E. B.
White
, “
Stability and transition of three-dimensional boundary layers
,”
Annu. Rev. Fluid Mech.
35
,
413
(
2003
).
4.
P.
Hall
,
M. R.
Malik
, and
D. I. A.
Poll
, “
On the stability of an infinite swept attachment line boundary layer
,”
Proc. R. Soc. London, Ser. A
395
,
229
(
1984
).
5.
W. E.
Gray
, “
The effect of wing sweep on laminar flow
,” RAE TM Aero No. 227,
1952
.
6.
U.
Dallmann
and
H.
Bieler
, “
Analysis and simplified prediction of primary instability of three-dimensional boundary-layer flows
,” in
19th AIAA, Fluid Dynamics, Plasma Dynamics, and Lasers Conference
(
American Institute of Aeronautics and Astronautics
,
1987
).
7.
M. V.
Ustinov
, “
Laminar-turbulent transition in boundary layers (review). Part. 1: Main types of laminar-turbulent transition in a swept-wing boundary layer
,”
TsAGI Sci. J.
44
,
1
(
2013
).
8.
A.
Dovgal
,
V.
Kozlov
, and
A.
Michalke
, “
Laminar boundary layer separation: Instability and associated phenomena
,”
Prog. Aerosp. Sci.
30
,
61
(
1994
).
9.
M.
Gaster
,
I.
Grant
, and
J. T.
Stuart
, “
An experimental investigation of the formation and development of a wave packet in a laminar boundary layer
,”
Proc. R. Soc. London, Ser. A
347
,
253
(
1975
).
10.
V. M.
Gilyov
,
Y. S.
Kachanov
, and
V. V.
Kozlov
, “
Development of a spatial wave packet in a boundary layer
,”
Izv. Sib. Otd. Akad. Nauk SSSR, Ser. Tekh. Nauk
13
(
3
),
27
(
1983
) (in Russian).
11.
Y. S.
Kachanov
, “
Development of spatial wave packets in boundary layer
,” in
Laminar-Turbulent Transition
, edited by
V. V.
Kozlov
(
Springer
,
Berlin Heidelberg
,
1985
), pp.
115
123
.
12.
Y. S.
Kachanov
and
T. G.
Obolentseva
, “
Development of three-dimensional disturbances in the Blasius boundary layer. 1. Wave-trains
,”
Thermophys. Aeromech.
3
(
3
),
225
(
1996
).
13.
Y. S.
Kachanov
and
T. G.
Obolentseva
, “
Development of three-dimensional disturbances in the Blasius boundary layer. 2. Stability characteristics
,”
Thermophys. Aeromech.
4
(
4
),
373
(
1996
).
14.
Y. S.
Kachanov
and
T. G.
Obolentseva
, “
Development of three-dimensional disturbances in the Blasius boundary layer. 3. Nonparallelism effects
,”
Thermophys. Aeromech.
5
(
3
),
331
(
1998
).
15.
W.
Würz
,
S.
Herr
,
A.
Wörner
,
U.
Rist
,
S.
Wagner
, and
Y. S.
Kachanov
, “
Three-dimensional acoustic-roughness receptivity of a boundary layer on an airfoil: Experiment and direct numerical simulations
,”
J. Fluid Mech.
478
,
135
163
(
2003
).
16.
Y. S.
Kachanov
and
D. B.
Koptsev
, “
Three-dimensional stability of self-similar boundary layer with a negative Hartree parameter. 1. Wave-trains
,”
Thermophys. Aeromech.
6
(
4
),
443
(
1999
).
17.
Y. S.
Kachanov
,
D. B.
Koptsev
, and
B. V.
Smorodsky
, “
Three-dimensional stability of self-similar boundary layer with a negative Hartree parameter. 2. Characteristics of stability
,”
Thermophys. Aeromech.
7
(
3
),
341
(
2000
).
18.
F. P.
Bertolotti
, “
Linear and nonlinear stability of boundary layers with streamwise varying properties
,” Ph.D. thesis,
The Ohio State University
,
1991
.
19.
D.
Romano
,
P.
Alfredsson
,
A.
Hanifi
,
R.
Örlü
,
N.
Tillmark
,
V.
Borodulin
,
A.
Ivanov
,
Y.
Kachanov
, and
M.
Minervino
, “
Design and tests of wind-tunnel sidewalls for receptivity experiments on a swept wing
,” in
Mechanical and Aerospace Engineering IV
, Applied Mechanics and Materials (
Trans Tech Publications
,
2013
), Vol. 390, pp.
96
102
.
20.
A.
Hanifi
,
S.
Hein
,
D.
Romano
,
M.
Minervino
,
W.
Würz
,
V.
Borodulin
,
A.
Ivanov
, and
Y.
Kachanov
, “
Numerical and experimental realization of an infinite-swept-wing boundary-layer flow in a wind tunnel
,” in
Proceedings of 17th International Conference on the Methods of Aerophysical Research
, edited by
V.
Fomin
(
ITAM SB RAS
,
Novosibirsk
,
2014
).
21.
V.
Borodulin
,
A.
Ivanov
, and
Y.
Kachanov
, “
Numerical and experimental realization of an infinite-swept-wing boundary-layer flow in a wind tunnel
,” in
Proceedings of 17th International Conference on the Methods of Aerophysical Research
, edited by
V.
Fomin
(
ITAM SB RAS
,
Novosibirsk
,
2014
).
22.
Y.
Kachanov
,
O.
Tararykin
, and
A.
Fedorov
, “
Investigation of stability of boundary layer on a model of a swept wing to stationary disturbances
,”
Izv. Sib. Otd. Akad. Nauk SSSR, Ser. Tekh. Nauk
5
,
11
(
1990
) (in Russian).
23.
A. V.
Ivanov
,
Y. S.
Kachanov
, and
D. A.
Mischenko
, “
Generation of nonstationary Görtler vortices by localized surface nonuniformities. Receptivity coefficients
,”
Thermophys. Aeromech.
19
,
523
(
2012
).
24.
V. R.
Gaponenko
,
A. V.
Ivanov
, and
Y. S.
Kachanov
, “
Experimental study of cross-flow instability of a swept-wing boundary layer with respect to traveling waves
,” in
Laminar-Turbulent Transition
, edited by
R.
Kobayashi
(
Springer
,
Berlin Heidelberg
,
1995
), pp.
373
380
.
25.
V. I.
Borodulin
,
A. V.
Ivanov
,
Y. S.
Kachanov
,
R.
Örlü
,
A.
Hanifi
, and
S.
Hein
, “
Characteristics of 3D instability of a 35-degree swept wing to CF and TS modes. Experiment and theory
,”
AIP Conf. Proc.
1770
,
030054
(
2016
).
26.
A. V.
Boiko
,
A. V.
Ivanov
,
Y. S.
Kachanov
, and
D. A.
Mischenko
, “
Steady and unsteady Görtler boundary-layer instability on concave wall
,”
Eur. J. Mech., B: Fluids
29
,
61
(
2010
).
27.
V. I.
Borodulin
,
A. V.
Ivanov
,
Y. S.
Kachanov
, and
D. A.
Mischenko
, “
Systematic study of distributed excitation of unsteady Görtler modes by freestream vortices
,”
Eur. J. Mech., B: Fluids
68
,
167
(
2018
).
28.
A.
Hanifi
,
D.
Henningson
,
S.
Hein
,
F.
Bertolotti
, and
M.
Simen
, “
Linear nonlocal instability analysis—The linear NOLOT code
,” Technical Report No. FFA TN 54,
1994
.
29.
S.
Hein
,
F.
Bertolotti
,
M.
Simen
,
A.
Hanifi
, and
D.
Henningson
, “
Linear nonlocal instability analysis—The linear NOLOT code
,” Technical Report No. DLR-IB 223-94 A43,
1994
.
30.
A. V.
Ivanov
,
Y. S.
Kachanov
, and
T. G.
Obolentseva
, “
Experimental study of Blasius boundary layer receptivity to localized surface vibrations
,”
Thermophys. Aeromech.
6
(
2
),
179
(
1999
).
31.
Y. S.
Kachanov
and
A.
Michalke
, “
Three-dimensional instability of flat-plate boundary layers: Theory and experiment
,”
Eur. J. Mech., B: Fluids
13
,
401
(
1994
).
32.
J. D.
Crouch
,
V. R.
Gaponenko
,
A. V.
Ivanov
, and
Y. S.
Kachanov
, “
Receptivity of swept-wing boundary layer to microscopic surface nonuniformities. Theory and experiment
,” in
Vth International Workshop on the Stability of Homogeneous and Heterogeneous Fluids Flows, Part III
(
NGASU
,
Novosibirsk
,
1998
), pp.
122
130
(in Russian).
33.
V. R.
Gaponenko
,
A. V.
Ivanov
, and
Y. S.
Kachanov
, “
Experimental study of a swept-wing boundary-layer stability with respect to unsteady disturbances
,”
Thermophys. Aeromech.
2
(
4
),
287
(
1995
).
You do not currently have access to this content.